Power brake device



Aug. 18, 1936. c. R. NORTH 2,051,150

POWER BRAKE DEVICE Filed Dec. l0, 1935 3 Sheets-Sheet l Aug. 18, 1936. C, RfNOR-rH l 2,051,150

POWER BRAKE DEVI CE Filed Dec. l0, 1955 3 Sheets-Sheet 2 Ili y;

Aug. 18, 1936. C. Rl NORTH 2,051,150

POWER BRAKE DEVICE Filed Dec. 10, 1955 3 Shee'ts-Sheet 3 'Patentes Aeg. 1s, 1936 UNITED STATES PATENT orrlcr.

POWER BRAKE DEVICE Charles B. North, Bruni, Tex.

Application December 10, 1935, Serial No. 53,820

4 Claims. (CI. 18S- 151) My invention relates to a power brake device, and has particular reference to a power brake device primarily intended for use in connection with well drilling apparatus and the like.

During the operation of drilling a well, such as an oil or gas well, it frequently becomes necessary for the operator or driller to insert and withdraw the drill stem from the well and, in the usual construction of well drilling apparatus, the cable drum from which the drill stem is suspended is provided with a brake drum with which is associated a hand-operated lever adapted to force an externally-contracting type of brake band into braking engagement with the brake drum to control and/or arrest the rotation of the cable drum. Due to the great weight of the ordinary drill stem and the great depth of the ordinary oil or gas well, it will be apparent that relatively great manual force is required to apply the brake band to the brake drum to control the speed of rotation of the cable drum and/or to completely arrest the rotation thereof. Cable drums of well drilling apparatus are usually provided with two brake drums, located at opposite ends of the cable drum and with two manually operable brake levers for applying the brake bands to the respective drums. Even by the use of two brake drums, it is extremely dimcult, if not impossible, for two or more operators or driliers to manually control the speed of rotation of the cable drum or to maintain the said drum against rotation.

It is an object of my invention to provide a power brake device in which fluid pressure is utilized to actuate the brake band which controls and/or arrests the rotation of the cable drum of well drilling apparatus.

It is an object of my invention to provide a power brake device in which fluid pressure is utilized to force a liquid, such as oil or the4 like, into a power cylinder located adjacent each brake band, whereby the brake band is forced into braking contact with the brake drum to control or completely arrest the rotation of the cable drum with which the power brake mechanisrn is associated.

It is an object of my invention to provide a compact and eiiicient power brake device for well drilling apparatus, which brake device includes a fluid-pressure actuated cylinder, a second cylinder actuated by the iluid pressure cylinder to force a fluid, such as oil or the like, into a third cylinder or set of cylinders, which last-mentioned cylinders effect the actuation of the brake bands, and to associate with said power brake device a novel spring arrangement fOr releasing the brake bands from the brake drums and returning the parts of the power brake device to their normal, inoperative positions.

It is a further object of my invention to provide means whereby the fluid can be retained in 5 the brake actuating cylinder or cylinders to thus maintain the brake bands in locked position on the brake drums to positively prevent rotation of the cable drum.

It is a still further object of my invention to lo y provide a power brake device that is simple in construction and operation, capable of attachment to the manually-operated brake device usually employed in connection with the well drilling apparatus of the prior art. and to pro- '15 vide a power brake device which is highly eflicient in the purposes for which designed.

Referring to the accompanying drawings forming al part of this specication, and wherein, for the purpose of illustration, I have shown a 20 preferred embodiment of my invention:

Figure 1 is a plan view of the preferred form of power brake device forming the subject-matter of my present application,

Fig. 2 is a side elevation of the power brake 25 device illustrated in Fig. 1 and showing the same attached to the external contracting brake bands on the cable drum of a standard well drilling apparatus,

Fig. 3 is a sectional view on the line 3-3 of 30 Fig. 1,

Figs. 4, 5 and 6 are vertical sectional views, respectively. of the main power cylinder, the fluid expelling cylinder operated by said main power cylinder, and one of the brake actuating cylin- 35 ders operated by the uid expelling cylinder to actuate the brake band into engagement with the brake drum,

Fig. 7 is a sectional view on the line 'l-1 of Fig. 1. 40

Fig. 8 is a side elevation of the main power cylinder and the uid expelling cylinder showing a modied spring arrangement for returning the pistons operating within said cylinders to their normal, inoperative positions, 45

Fig. 9 is a vertical sectional view showing the fluid expelling cylinder partly in section and showing the supply tank associated with said fluid expelling cylinder for supplying uid, such as oil or the like, to the iluid expelling cylinder, 50 and Fig. 10 is a vertical sectional view on the line IU--Iil of Fig. 9.

In the accompanying drawings. wherein like numerals are employed to designate like parts 55 throughout the several views, the numeral I designates a brake drum attached to one end .of the cable drum oi' a standard well drilling apparatus. Encircling the brake drum is a brake band 2l of the external-contracting type, one Vend of said band being xed to the base structure 3 by a connection 4, and the opposite end being connected to a cross pin 5 positioned within an lelongated slot 6 in a lever 1 pivoted at its lower end at 8 to a bracket 9 ilxed on the base structure 3. It-will be obvious to one skilled in the art that by moving the lever 1 in a clockwise direction about its pivotal mounting 8, the brake band 2 will be forced into frictional engagement with the periphery voi the brake drum I to either slow up or completely arrest the rotation of said brake drum and the cable drum to which it is attached.

My improved power brake device for positively actuating the brake bands 2 comprises a main power cylinder consisting oi' a cylindrical sleeve portion III externally threadedV at its opposite ends and provided with internally threaded head or closure members II and I2, adapted to be'screwed onto'opp'osite ends of said sleeve portion III. As a preferred means of mounting the main power cylinder, I provide an elongated base member I3 having near one end thereof a pair of spaced, upstanding, rectangular plates Iland- I5. The plates I4 and I5 are provided with aligned openings slightly greater in diameterthan the external diameter oi the sleeve portion I9. When assembling the main power cylinder upon the base member I3, the sleeve portionV I9 is passed through the aligned openings in the plates I4 and I5 and the head or closure members II and I2 are screwed onto opposite ends of said sleeve portion I0 until the inner ends of said head or closure members abut .against the outer faces of the plates I4 and I5,

respectively, thus retaining the main power cylinder in fixed position upon the base member I3.' 'I'he head or closure member II is provided with a pair of spaced apertures, to one of which is connected the inlet valve I6 leading from a source of iluid pressure, and to the other of which is connected an exhaust valve I1 leading to atmosphere. The valves I 9 and I1 are prei.'- erably 'of the rotary plug type and, while such valves may be individually or independently operated. they are preferably arranged so that the opening or passage through one plug is disposed at right angles to the opening or passage through the other plug. By pivotally connecting the valve operating handles I 8v and I9 to a common operating rod 29, it will be obvious that the two valves lcan be operated from a remote position, and that reciprocationof the operatingrod 20 will alternately open and close the respective valves, i. e., when the operating rod 20 is moved to open the valve I9 to admit iluid pressure into the main power cylinder, the valve I1 jwill be closed, and when the operating rod is moved to open the exhaust valve I1, the valve I 9 will be closed. Within the main power cylinder is a piston 2I provided with suitable packing rings 22 and connected to a piston rod 23 which extends through an opening in the head or closure member I2 and is screw-threaded at its outer end. In order to prevent the escape of iluid pressure from the main power cylinder, I provide a packing 24 adapted to be compressed into iirm engagement with the piston rod 23 by means of the packing nut 29. The head or closure member I2 is provided with an opening III to permit the entry and escape ot air as the piston 2| moves back and i'orth within the cylinder I0.

At that end ofthe base member I3 opposite the main power cylinder, I provide a pair of spaced, upstanding, rectangular plates 23 and 21 provided with aligned openings voi' a diameter slightly greater than the external diameter oi the duid-ejecting cylinder. which cylinder oomprises a sleeve portion 2l screw-threaded at its oppositeV ends and provided with internally threaded head or closure members 29 and 30, adapted to screw onto opposite ends of the sleeve portion 28. In order to mount the iluidejecting cylinder upon the base member I3, I pass the cylindrical sleeve portion 2l through the aligned openingsin the plates 29 and 21 \and screw the head or closure members 29 and 39 onto opposite ends of said sleeve portion until the inner ends of said head or closure members abut against the outer faces o! the plates 26 and 21, respectively, thus retaining the illudejecting cylinder in ilxed position upon the base member I3. Within the huid-ejecting cylinder above described, I provide a piston-3| having suitable packing rings 32 and provided with a piston rod 33 which piston rod extends through a centrally-positioned aperture in the head or closure member 29. The head or closure member 29 is provided with an opening 34 to permit the entry and escape of air as the piston 3| moves back and `i'orth within the cylinder. The head or closure member 30 is provided with a pair of openings, into one o! which is threaded a pipe 35. and into the other of which is connected a pipe 39 which leads to a iluid supply tank 31 positioned above the duid-ejecting cylinder, the pipe 36 being provided with a check valve 38 which permits the iluid, such as oil or the like,to ilow from the tank 31 to the fluidejecting cylinder but which is effective to prevent the flow of fluid from said cylinder to the said tank. The tank 31 is provided with a removable plug 39, which, when removed, permits oil or other uid to be introduced into the tank. In order to strengthen the supporting structure and to providea ready means i'or supporting the supply tank 31 in a position above the iluid-ejecting cylinder, I provide a pair of rods 40 and 4I which pass through aligned apertures near the side edges of the platesA I4, Il, 23 and 21. These rods 40 and 4I are threaded at their opposite ends and intermediate their lengths to receive nuts 42, and to further strengthen the supporting structure, I provide a pair of spacing sleeves 43 and 444 placed upon the rods 40 and 4I, respectively, and positioned between each of the upstanding plates I4 and I9, and 29 and 21. As a convenient means for supporting the tank 31 in a position above the Huid-ejecting cylinder, I secure to the bottom of said tank pairs of spaced clamps 45 and 46, the outer ori'ree ends oi which engage beneath the rods 49 and 4I, to which rods they are rigidly secured by means of bolts 41 and 49 which pass through the openings in the clamps 45 and. and are threadedinto openings in .the said rods 4`9'and 4I.

The piston rods 23 and 33 extend toward each other in axial alignment and their outer, freeends are secured together by means of a coupling 49, into which the ends oi' the two piston rods are 70 springs 52, the opposite ends oi which are se- 75 cured to hook members 63 which are bolted to the upstanding plate l5. The lengthbf the springs 52 is such that they are not extended or placed under tension when the piston 2| is positioned at the left hand end of the main power cylinder, as viewed in Figs. l, 2 and 4. It will be obvious that as the piston 2| moves toward the fluidejecting cylinder, these springs 52 are placed under tension, and that when fluid pressure is released from within the main power cylinder, these springs contract and are effective to return the pistons within the main power cylinder and within the fluid-ejecting cylinder, to their normal, inoperative positions.

'I'he pipe 35 connected to the fluid-ejecting cylinder, is provided with a pressure gauge 54 and is connected by means of a T-coupling or union 55, to two branch pipes 56 and 51 which lead to a pair of brake-actuating cylinders 58 and 59, respectively. Each of the said brake-actuating cylinders 58 and 59, comprises a cylindrical sleeve portion 60 externally threaded at its opposite ends and provided with internally threaded head or closure members 6| and 62, adapted to be screwed onto opposite ends of said sleeve portion 60. Within each of the cylinders 58 and 59 is a piston 63 provided with suitable packing rings 64 and connected to a piston rod 65 which extends through an opening in the head or closure member 62, which member 62 is also provided with an aperture 66 to permit entry and escape of air as the piston 63 moves back and forth within the cylinder. The branch pipes 56 and 51 extend into and through the head or closure member 6| of each of the respective brake-actuating cylinders 58 and 59, each of the branch pipes 56 and 51 being provided with a valve 61 and 68, respectively. The valves 61 and 68 are preferably of the rotary plug type and while such valves may be individually or independently operated, they are preferably arranged so that the opening or passage through one plug is parallel to the opening or passage through the other plug. By pivotally connecting the valve operating handles 69 and 10 to a common operating rod 1|, it will be obvious that the two valves 61 and 68 can be operated from a remote position, and that reciprocation of the operating rod 1| will simultaneously open or close the two valves 61 and 68. Each of the pipes 56 and 51 passes through a horizontally-extending, centrally-apertured, cross bar 12 which abuts against the outer face of the head or closure member 6| of each cylinder 58 and 59, and which is provided with a pair of hook members 13 and 14 which pass through suitable apertures near the outer ends of each cross bar. The piston rod 65 of each cylinder 58 and 59 passes through a sleeve member 15 which is rigidly secured to the said rod by means of a set screw 16. Each sleeve member 15 carries a. pair of radiallyextending, horizontal arms 11 and 18, at the outer ends of which are secured hook members 19 and 80. A relatively strong tension spring 8| extends between the hook members 13 and 19 and 14 and 80, the length of each spring 8| corresponding substantially to the length of the cylinders 58 and 59, i. e., the length of each spring 8| is such that when the piston 63 is in the position shown in Fig. 6, the spring 8| is not extended or placed under tension. With this arrangement, it will be obvious that as the piston 63 is forced toward the right as viewed in Fig. 6, each spring 8| will be stretched or placed under tension, and when the pressure within the cylinder is relieved, each spring 8l will contract and will return the pistons 63 to their normal, inoperative positions. 'I'he outer free end of each piston rod 65 is provided with a sleeve member 82, keyed or otherwise secured to said rod, each sleeve member 62 having an upwardly-extending arm 83 provided near its upper end with an aperture 84 through which is passed and secured a bolt, rivet or the like to secure the said upstanding arm to a lug 85 depending from the brake band 2.

In Fig. 8 of the accompanying drawings, I have shown an alternative construction in which vthe 4springs 52 have been omitted and a novel spring arrangement provided for returning the pistons 2| and 3| to their normal, inoperative positions within the main power cylinder and fiuid-ejecting cylinder, respectively. In this form of my invention, a bolted-flange type of coupling 86 secures the adjacent ends of the piston rods 23 and 33 together. A flanged sleeve member 81 is mounted on the rod 33 adjacent the coupling 86 and a second iianged sleeve member 88 is mounted on the rod 33 adjacent the head or closure member 29 of the fluid-ejecting cylinder. Positioned between the flanged sleeve members 81 and 88 and surrounding the piston rod 33, is a relatively heavy compression spring 89. It will be obvious that as uid pressure is introduced into the main power cylinder the piston 2| and the rod 23 secured thereto will be forced toward the iluid-ejecting cylinder. This movement of the piston rod 23 will, through the coupling 86, force the piston rod 33 and the piston 3| carried thereby into the iluid-ejecting cylinder. Such movement will compress the spring 89 between the flanged sleeve members 81 and 88, it being obvious that when fluid pressure within the main power cylinder is released, said spring will expand from its compressed condition which will result in the return of the pistons 2| and 3| to their normal, inoperative positions.

It is believed that the operation of the power brake device above described will be readily apparent to one skilled in the art from a consideration of the above described construction. Sufiice it tg say that when it is desired to control the rotation of the cable drum of the well drilling apparatus by application of the brake band 2 to the brake drum l, uid pressure, such as steam, compressed air or the like, is admitted to the main power cylinder by actuation of the control rod 29 which moves the inlet valve I6 to open position and simultaneously closes the exhaust valve i1. The fluid pressure admitted to the main power cylinder forces the piston 2| and the piston rod 23 attached thereto, toward the right as viewed in Fig. 4, this movement expanding or extending the springs 52. As the piston 2| is forced out of the main power cylinder, the connection between the piston rods 23 and 33 causes the piston 3| within the iiuid-ejecting cylinder, to move toward the right as viewed in Fig. 5, thus expelling the oil or other fluid from the said cylinder, through the pipes 35, 56 and 51 into the brake-actuating cylinders 58 and 59. During this operation, it is assumed that the rod 1| has been actuated to simultaneously open the valves 61 and 68. By observing the pressure gauge 54, the operator may determine the degree of pressure of the oil or other uid forced through the pipes 3s, se and s1 inw the brakeviewed in Fig. 6, thus ejecting the piston rods from the ends of the cylinders, and placing the springs 8| under tension. The outward movement of the piston rods 65 operates through the connections I2, Il, u and I5, to move the brake band 2 toward the right as viewed in Fig. 2, this action resulting in the contracting of the brake band into frictional `contact with the periphery of the brake drum I to slow down or completely arrest the rotation of the said drum and the cable drum to which it is attached. If it is desired to maintain the cable drum in nonrotating position, the valves 61 and 68 are simultaneously actuated to closed position by the rod 1l, thus retaining the oil or other uid within the brake-actuating cylinder and locking the brake drum against rotation.

When it is desired to release the brake band 2 from contact with the brake drum I, the actuating rod 20 is moved to close the inlet valve I6 and open the exhaust valve I1. 'I'his permits the steam or other pressure fluid to escape from the main power cylinder, whereupon the springs 52 will function to return the piston 2| to its normal, inoperative' position.l Assuming that the valves 61 and 'l0 are open, the movement of the piston 42i into the main power cylinder will likewise draw the piston 3l of the iluid-ejecting cylinder into itsl normal, inoperative position, this movement of the piston Il drawing the oil or other fluid from the brakeactuating cylinders 58 and. 59 and permitting the springs 8| to return the pistons 63 and the parts carried thereby to their normal, inoperative positions. As the piston 63 moves into the brake-actuating cylinders 58 and 59 the brake band is removed from frictional contact with the periphery of the brake drum l, thus permitting rotation of the brake drum and the cable drum to which said brake drum is attached. In the event of failure of the power brake device, or if for any reason it should not be desired to actuate the brake by means thereof, it will be obvious that the lever 1 may be manually actuated to force the brake band 2 into contact with the brake drum. Referring to the modified construction shown in Fig. 8, it will be obvious that the spring 09 will beV effective to return the pistons 2| and 3| to their normal, inoperative positions following the opening of the exhaust valve Il and the escape of fluid pressure from within the main power cylinder, i. e., in this modified construction the spring 89 accomplishes the same results accomplished by the springs Il above referred to.

It will be understood that the forms of my invention herein shown and described are to be taken as preferred embodiments of my invention and that various changes in the detailed construction and operation may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A power brake device for actuating a brake band into frictionai contact with a brake drum, said device comprising a base structure having a pair of spaced, apertured, upstanding plates. the apertures in the plates being in horizontal alignment; a fluid pressure actuated main power cylinder comprising a central portion passing through the aligned apertures in the plates and extending beyond the outer faces of said plates, and head or closure members secured to said central portion at opposite ends thereof, said h'ead or closure members'having portions con-- the exterior of said cylinder; a duid-electing cyl- 5 inder having a piston therein with a piston rod extending to the exterior of the cylinder; means for connecting the piston rods so that fluid pressure admitted to the main power cylinder will eject the fluid from the iluid-ejecting cylinder; l and a brake-actuating cylinder receiving uid under pressure from said fluid-electing cylinder and havinga piston therein with a piston rod extending to the exterior of the said cylinder, said piston rod being connected to the brake band l to force said band into frictional contact with said brake drum.

2. A power brake device for actuating a brake band into frictional contact with a brake drum, said device comprising a base structure having spaced pairs of apertured, upstanding plates, the apertures in each pairA of plates being in horizontal alignment; a fluid pressure actuated main power cylinder comprising a central portion passing through the aligned apertures in one pair of plates and extending beyond the outer faces of said plates, and head or closure members secured to said central portion at opposite ends thereof, said head or closure members having portions contacting the outer faces of said plates to rigidly support the main power cylinder in position on said plates, said main power cylinder 4having a piston therein with a piston rod extending to the exterior of the cylinder; a fluid-ejecting cylinder comprising a central portion passing through the aligned apertures in the other pair of plates and extending beyond the outer faces of said plates, andrhead or closure members secured to said central portion at opposite ends thereof, said head or closure members having portions contacting the outer faces of said plates to rigidly support the fluid-ejecting cylinder in position on said plates, said fluid-electing cylinder 'having a piston therein with a piston rod extending to the exterior of the cylinder; means for connecting the piston rods so that fluid pressure admitted to the main power cylinder will eject the fluid from the fluid-electing cylinder; and a brakeactuating cylinder receiving fluid under pressure from said iluid-ejecting cylinder and having a piston therein with a piston rod extending to the exterior of the said cylinder, said piston rod being connected to said brake band to force the band into frictional contact with said brake drum.

'3. A power brake device for actuating a brake band into frictional contact with a brake drum, said device comprising a base structure having upstanding plates near opposite ends thereof; a fluid pressure actuated, main power cylinder supported by one of said plates and having a piston therein with a piston -rod extendingto the exvterior of the cylinder; a fluid-electing cylinder supported by the other of said plates and having a piston therein with a piston rod extending to the exterior of the cylinder; a reinforcing and strengthening rod extending through said upstanding plates withclamping nuts secured to the ends of said rod'and bearing -against the outer faces of said plates, means for connecting the piston rods so that fluid pressure admitted to the main power cylinder will eject the fluid from the fiuid-ejecting cylinder; and a brakeactuating cylinder receiving fluid under pressure from said fluid-ejecting cylinder and having a piston therein with a piston rod extending to the 75 exterior of the said cylinder, said piston rod being connected to said brake band to force the band into frictional contact with said brake drum.

4. A power brake device for actuating a brake band into frictional contact with a brake drum, said device ,comprising a base structure having upstanding plates near opposite ends thereof; a uid pressure actuated, main power cylinder supported by one of said plates and having a piston therein with a piston rod extending to the exterior of the cylinder; a fluid-ejecting cylinder supported by the other of said plates and having a piston therein with a piston rod extending to the exterior of the cylinder; a pair of reinforcing and strengthening 'rods positioned above said uid-ejecting cylinder and extending through said upstanding plates near the upper and outer corners thereof with clamping nutsy secured to the ends of said rods and bearing against the outer faces of said plates; a supply tank supported on said reinforcing and strengthening rods and connected to said fluid-ejecting cylinder for supplying fluid thereto; means for connecting the piston rods so that fluid pressure admitted to the main power cylinder will eject the iluid from the fluid-ejecting cylinder; and a brake-actuating cylinder receiving iiuid under pressure from said l0 iuid-ejecting cylinder and having a piston therein with a piston rod Aextending to the exterior of the said cylinder, said piston rod being connected to said brake band to force vthe band into frictional contact with said brake drum.

CHARLES R. NORTH. 

